Michael, you can't use dog training as any comparison to parrot training. Leaving aside the fact that dogs have been domesticated for, at least, 30,000 years, dogs descend all from the grey wolf which has a hierarchical social grouping where the puppies and young adults strive to please the alpha - parrots don't.
As to learning to do kissy noises, throwing a ball, etc. I think that learning or adopting behaviors that bring the reward of attention or love ON THEIR OWN is not the same as having training sessions for tricks.
My beef with trick training for parrots is that it's like crate training for dogs. I don't use crates to train my dogs at home (I don't need them for my dogs to learn what I want them to learn, same as I don't do target or clicker training with my parrots) but I have used them at the shelter and, when you use the crate as a training tool in a judicious manner (just for the perfect number of hours, at the right time, etc), the technique is invaluable, BUT when you use it wrong, you end up with a mal-adjusted animal that almost always ends up in a shelter. And I know because I have such a dog right now and have had experience with many of them at the rescue.
Basically, my point is that teaching parrot trick training techniques is a double-edged sword because you can teach the techniques but you can neither teach common sense nor can you instill love/compassion for the animal. Therefore, what can be a benefit to the bird in terms of rewarding interaction, enrichment, etc. when done right can end up been the weapon of their destruction when done by the wrong person because, unfortunately, trick training, with its 'YouTube showoff' factor, has a much higher chance of been done only for personal reward than to benefit the bird.
The bird in question is only four months old (FOUR months old - a baby, for heavens sake!). He is been trained several times a day and I would bet the owner does food management, too, as recommended in Michael's book. And let's not forget this is a sun conure, not what one would call the sweetest-tempered bird there is! It's worrisome to say the least...